Mechanically driven electric generators for aircraft engines, such as turbine engines, are well known. Such mechanically driven generators use electromagnetic induction to generate electricity. This is accomplished by extracting mechanical energy from moving parts of the engine.
Extracting mechanical energy reduces the amount of energy available for the primary purpose of the engine, which is typically to propel the aircraft forward. Thus, the use of such mechanically driven electric generators inherently reduces the efficiency of the engine.
Further, the use of such mechanically driven electric generators increases fuel consumption and consequently increases the costs associated with increase fuel consumption, wear, and maintenance. Increased fuel consumption creates increased pollution.
When an aircraft is initially designed, the electrical requirements for the aircraft are determined and electric generators are selected based upon those requirements. Generally, the smallest and lightest electric generators that fulfill the electrical requirements of the aircraft are selected. Thus, such electric generation systems do not typically have substantial spare capacity.
The life span of an aircraft can be several decades. During its life time, several iterations of avionics and electrical systems can occur. Many of these newer avionics and electrical systems find their way into older airframes, which have older electric generators. Upgrading avionics and installing new electrical devices can substantially increase the demand for electrical power. This increased demand can exceed the capacity of the installed electric generators.
In order to try to optimize aerodynamic efficiency, all of the systems in the turbine engine nacelle are packaged tightly. There is typically no room for the installation of additional or larger electric generators. Thus, upgrading to a larger electric generator can require costly modifications to the turbine engine and nacelle. Such modifications can include replacing the power extraction shaft, gearboxes, and mounting pad. In some instances, undesirable changes to the nacelle mold line are necessitated.
As such, there is a need for a way to generate electricity from a turbine engine or the like, which requires comparatively little space and thus necessitates comparatively little modification of the turbine engine.